¹ Jus ad bellum refers to the conditions under which one may resort to war or to force in general; jus in bello governs the conduct of belligerents during a war, and in a broader sense comprises the rights and obligations of neutral parties as well.

² Haggenmacher, P., Grotius et la doctrine de la guerre juste, Paris, 1983, pp. 250 ff. and 597 Google Scholar ff., and “Mutations du concept de guerre juste de Grotius à Kant”, Cahiers de philosophie politique et juridique, No. 10, 1986, pp. 117–122.Google Scholar

³ There is an abundant literature on the concept of just war.

For the Graeco-Roman period in particular, see Clavadetscher-Thürlemann, S., Polemos dikaios und bellum iustum: Versuch einer Ideengeschichte, Zurich, 1985 Google Scholar; Mantovani, M., Bellum iustum: Die Idee des gerechten Krieges in der romischen Kaiserzeit, Bern/Frankfurt am Main, 1990 Google Scholar; Albert, S., Bellum iustum: Die Theorie des gerechten Krieges und ihre praktische Bedeutung für die auswärtigen Auseinandersetzungen Roms in republikanischer Zeit, Lassleben, 1980 Google Scholar; Hausmaninger, H., “Bellum iustum und iusta causa belli in älteren romischen Recht”, Oesterreichische Zeitschrift für öffentliches Recht, 1961, Vol. 11, pp. 335 ffGoogle Scholar.

For the Middle Ages in particular, see Russell, F.H., The just war in the Middle Ages, Cambridge/London, 1975 Google Scholar; Hubrecht, G., “La guerre juste dans la doctrine chrétienne, des origines au milieu du XVI^e siècle”, Recueil de la Société Jean Bodin, 1961, Vol. 15, pp. 107 ff.Google Scholar; Salvioli, J., Le concept de la guerre juste d'après les écrivains antérieurs à Grotius, 2nd ed., Paris, 1918 Google Scholar; Vanderpol, A., La doctrine scolastique du droit de la guerre, Paris, 1925, p. 28 Google Scholar ff., and Le droit de la guerre d'après les théologiens et les canonistes du Moyen Age, Paris/Brussels, 1911 Google Scholar; Beesterm-Iler, G., Thomas von Aquin und der gerechte Krieg: Friedensethik im theologischen Kontext der Summa Theologica, Cologne, 1990 Google Scholar.

On the notion of just war in general, see Haggenmacher, , Grotius, op. cit. Google Scholar; Elshtain, J.B., The just war theory, Oxford/Cambridge (Mass.), 1992 Google Scholar; Regout, R., La doctrine de la guerre juste de Saint Augustin à nos jours, Paris, 1935 Google Scholar; Beaufort, D., La guerre comme instrument de secours ou de punition. La Haye, 1933 Google Scholar; Walzer, M., Just and unjust wars: A moral argument with historical illustrations, 2nd ed., New York, 1992 Google Scholar; Brière, Y. de la, Le droit de juste guerre, Paris, 1938 Google Scholar; Draper, G.I.A.D., “The just war doctrine”, Yale Law Journal, Vol. 86, 1978, pp. 370 ff.CrossRefGoogle Scholar; Szetelnicki, K., Bellum iustum in der katholischen Tradition, Fribourg, 1992 Google Scholar.

On the relationship with the Muslim doctrine of war, see Johnson, J.T., Just war and Jihad: Historical and theoretical perspectives on war and peace in Western and Islamic tradition. New York/London, 1991 Google Scholar; Steinweg, R., Der gerechte Krieg: Christentum, Islam, Marxismus, Frankfurt am Main, 1980.Google Scholar

⁴ Haggenmacher, , Grotius, op. cit., pp. 457 ff.Google Scholar, and “Mutations”, art. cit., pp. 108–109.Google Scholar

⁵ Grotius, De iure belli ac pacis (1625), Book II, chap. I, 2, 1. See Haggenmacher, , Grotius, op. cit., pp. 549 ff.Google Scholar

⁶ Haggenmacher, , Grotius, op. cit., pp. 457 ff., 547 ff, and 568 ffGoogle Scholar., and “Mutations”, art. cit., pp. 110–113.Google Scholar

⁷ Grotius, , op. cit. Google Scholar, Book III, chaps. XI–XVI (see Haggenmacher, , Grotius, op. cit., pp. 600 ff.).Google Scholar

⁸ Haggenmacher, , Grotius, op. cit., pp. 600 ff.Google Scholar

⁹ The rule limiting the competence to wage war to the public authorities (i.e. the sovereign) is affirmed in an oft-quoted passage of St Thomas Aquinas which sets out the three prerequisites for such competence: auctoritas principis, justa causa and recta intentio (Summa theologica, II, II, 40, 1). See Schilling, O., Das Volkerrecht nach Thomas von Aquin Google Scholar, Freiburg im Breisgau/Berlin, 1919. On recta intentio, see Haggenmacher, , Grotius, op. cit., pp. 401 ff.Google Scholar

¹⁰ See below.

¹¹ Grotius, , op. cit. Google Scholar, prolegomena, para. 28: “Ego cum ob eas, quas jam dixl, rationes, compertissimum haberem, esse aliquod inter populos ius commune, quod & ad bella & in bellis valeret…”. See also Book I, chap. I, 3, 1: “De iure belli cum inscribimus hanc tractationem, primum hoc ipsum intelligimus, quod dictum jam est, sitne bellum aliquod iustum, & deinde quid in bellum iustum sit”. (In giving our treatise the title The law of war, we first wish to examine, as we have said, whether war can be just and what is just in war. — ICRC translation.)

¹² Haggenmacher, , Grotius, op. cit., p. 601.Google Scholar

¹³ Haggenmacher, , “Mutations”, art. cit., pp. 113–117.Google Scholar

¹⁴ Haggenmacher, , Grotius, op. cit., pp. 599 and 605 Google Scholar ff., and “Mutations”, art. cit., pp. 117 ff.Google Scholar

¹⁵ On this dichotomy, see Haggenmacher, , “Mutations”, art. cit., pp. 107–108.Google Scholar

¹⁶ Haggenmacher, , Grotius, op. cit., p. 599.Google Scholar

¹⁷ De iure belli relectiones, Nos. 15 ff. (lawful motives for war) and Nos. 34 ff. (just limits in the law of war). See Haggenmacher, , Grotius, op. cit., pp. 171–172 and 611.Google Scholar

¹⁸ Jus gentium methodo scientifica pertractatum (1749)Google Scholar, paras. 888 ff. See Haggenmacher, , Grotius, op. cit., pp. 607–608 Google Scholar, and “Mutations”, art. cit., pp. 118–189.Google Scholar

¹⁹ Le droit des gens (1758), Vol. III Google Scholar, chap. VIII. See Haggenmacher, , Grotius, op. cit., pp. 609–610 Google Scholar, and “Mutations”, art. cit., p. 119.Google Scholar

²⁰ Metaphysik der Sitten, Rechtslehre, para. 53.

²¹ As N. Politis puts it with his usual elegance in Les nouvelles tendances du droit international (Paris, 1927, pp. 100–101)Google Scholar: “Sovereignty killed the theory of justum bellum. The States' assertion that they did not have to account for their deeds led them to claim the right to use the force at their disposal as they saw fit” — ICRC translation)

²² Wehberg, H., The outlawry of war, New York, 1931 Google Scholar, and “La mise de la guerre hors la loi”, Recueil des Cours de l'Académie de droit international de La Haye (RCADI), 1928–IV, Vol. 24, pp. 146 ff.Google Scholar; Morrison, C.C., The outlawry of war: A constructive policy for world peace, Chicago, 1927 Google Scholar; and Wright, Q., “The outlawry of war”, American Journal of International Law (AJIL), 1925, Vol. 19, pp. 76 ff.CrossRefGoogle Scholar

²³ See for example Saint Augustine, De civitate Dei, I, 1, and Epistula CXXXVI.

²⁴ Saint Augustine, De civitate Dei, I, 1; I, 6; XIX, 23.

²⁵ Ibid.

²⁶ Grotius, De iure praedae, chap. VII, art. III–IV.

²⁷ Ibid.

²⁸ Grotius, De iure belli ac pads, Book III, chap. I, 1.

²⁹ Timbal, P.C. (ed.), La guerre de Cent Ans vue à travers les registres du Parlement (1337–1369), Paris, 1961, p. 541.Google Scholar

³⁰ Knighton, H., Chronicle, Vol. II, London, 1985, p. 111 Google Scholar. Also see the note of Edward III concerning the Ivo de Kerembars affair, in Keen, M.H., The laws of war in the Middle Ages, London/Toronto, 1965, p. 29, note 1.Google Scholar

³¹ G. Baker of Swinbrook, Chronicon, Oxford, 1889, pp. 86, 96 and 154.Google Scholar

³² Keen, M.H., “Treason trials under the law of arms”, Transactions of the Royal Historical Society, 5th series, 1962, Vol. 12, p. 96 CrossRefGoogle Scholar. See also the letter from N. Rishdon to the Duke of Burgundy, in Keen, , The laws of war, op. cit., p. 17.Google Scholar

³³ Hayez, M., “Un exemple de culture historique au XVe siècle: la Geste des nobles français”, Mélanges d'archéologie et d'histoire de l'Ecole française de Rome, 1963, Vol. 75, p. 162 Google Scholar; Keen, , The laws of war, op. cit., p. 1.Google Scholar

³⁴ See the cases of David Margnies vs Prévôt de Paris (Parlement de Paris, ca 1420) and of Jean de Melun vs Henry Pomfret (Parlement de Paris, 1365), in Keen, , The laws of war, op. cit., pp. 18 and 260.Google Scholar

³⁵ Luce, S., Histoire de Bertrand du Guesclin et de son époque. Lajeunesse de Bertrand du Guesclin, 1320–1364, Paris, 1876, pp. 600–603.Google Scholar

³⁶ Bueil, J. de, Le Jouvencel, Vol. II, Paris, 1889, p. 91.Google Scholar

³⁷ Contamine, P., Guerre, état et société à la fin du Moyen Age. Etudes sur les armées des rois de France, 1337–1494, Paris/The Hague, 1972, p. 187.CrossRefGoogle Scholar

³⁸ Martens, G.F. de, Précis du droit des gens moderne de l'Europe, 3rd ed., Gottingen, 1821, p. 462 Google Scholar, quoting an author writing in 1745; C. Lüder, in Holtzendorff, F. (ed.), Handbuch des Völkerrechts, Vol. IV, Hamburg, 1889, p. 254.Google Scholar

³⁹ For all these examples and others, see Contamine, Guerre, état et société, op. cit., pp. 187 ff.; Keen, , The laws of war, op. cit., pp. 1 ffGoogle Scholar; Audinet, E., “Les lois et coutumes de la guerre à l'époque de la guerre de Cent Ans”, Memoires de la Société des Antiquaires de l'Ouest, 1917, Vol. 9.Google Scholar

⁴⁰ Keen, , The laws of war, op. cit., pp. 7–22 Google Scholar. It was only in the sixteenth century, at the time of the School of Salamanca, that jus belli took on the meaning that it has today in public law. See Haggenmacher, , Grotius, op. cit., p. 283.Google Scholar

⁴¹ Keen, , The laws of war, op. cit., p. 10 ffGoogle Scholar. On the concept of jus gentium, see inter alia Voigt, M., Das ius naturale, aequum et bonum und ius gentium der Romer, 4 Google Scholar vol., Aalen, reprint, 1966 (1st ed., Leipzig, 1856–1875); Lombardi, G., Sul concetto di ius gentium, Milan, 1974 Google Scholar; Kaser, M., Ius gentium, Cologne/Weimar, 1993 Google Scholar; Lauria, M., “Ius gentium”, Mélanges P. Koschaker, Vol. I, Weimar, 1939, pp. 258 ff.Google Scholar; Frezza, P., “Ius gentium”, Revue internationale des droits de l'Antiquité, 1949, Vol. 2, pp. 259 ff.Google Scholar; Haggenmacher, , Grotius, op. cit, pp. 313 ff.Google Scholar

⁴² History of Rome, Book II, 12, and Book XXXI, 30: “Esse enim quaedam belli jura, quae ut facere ita pati sit fas”.

⁴³ Heffter, A.G., Le droit international de l'Europe, 4th ed., Berlin'Paris, 1883, p. 260.Google Scholar

⁴⁴ Histories, Book V, 9, 11.

⁴⁵ Nys, E., Les origines du droit international, Bruxelles/Paris, 1894, p. 208.Google Scholar

⁴⁶ See for example Ward, R., An enquiry into the foundations and history of the law of nations in Europe, Vol. II, London, 1795, p. 165 Google Scholar; and Phillimore, R., Commentaries upon international law, Vol. II, London, 1857, p. 141.Google Scholar

⁴⁷ See for example de Martens, Précis du droit, op. cit., p. 461 Google Scholar, para. 270, “Loix de la guerre”.

⁴⁸ See Actes et documents relatifs au programme de la Conférence de la Pah, The Hague, 1899 Google Scholar; and Actes et documents: Deuxième Conférence internationale de la Paix, La Haye, 15 juin–18 octobre 1907, 3 vol., The Hague, 1907.Google Scholar

⁴⁹ Enriques, G., “Considerazioni sulla teoria della guerra nel diritto internazionale”, Rivista di diritto internazionale, 1928, Vol. 20, p. 172.Google Scholar

⁵⁰ Keydel, H., Das Recht zum Kriege im Völkerrecht, Frankfurter Abhandlungen zum moderne Völkerrecht, No. 24, Leipzig, 1931, p. 27.Google Scholar

⁵¹ Strupp, K., “Les règies générates du droit de la paix”, RCADI, 1934–1, Vol. 47, p. 263 ff.Google Scholar

⁵² On the Vienna neopositivist school of philosophy, see Kraft, V., Der Wiener Kreis: Der Ursprung des Neopositivismus, 2nd ed., Vienna/New York, 1968 Google Scholar. On the legal school of Vienna, see Kunz, J., The changing law of nations, Toledo, 1968, pp. 59 ff.Google Scholar; and Stone, J., The province and function of law, Cambridge (Mass.), 1950, pp. 91 ff.Google Scholar

⁵³ “Bellum justum and bellum legale”, AJIL, 1951, Vol. 45, pp. 528 ff.Google Scholar

⁵⁴ “Plus de lois de guerre?”, Revue générale de droit international public (RGDIP), Vol. 41, 1934, p. 22.Google Scholar

⁵⁵ Kriegsrecht und Neutralitätsrecht, Vienna, 1935, pp. 1–2.Google Scholar

⁵⁶ Völkerrecht, Berlin, 1937, p. 289.Google Scholar

⁵⁷ Völkerrecht, 2nd ed., Berlin, 1950, p. 337.Google Scholar

⁵⁸ La doctrine de la guerre juste de saint Augustin à nos jours, Paris, 1935, pp. 15 ff.Google Scholar

⁵⁹ The legal position of war: Changes in its practice and theory from Plato to Vattel, The Hague, 1937, p. 2.Google Scholar

⁶⁰ Guggenheim, P., Lehrbuch des Völkerrechts, Vol. II, Basel, 1949, p. 778.Google Scholar

⁶¹ See for example Grob, F., The relativity of war and peace, New Haven, 1949, pp. 161 and 183–185.Google Scholar

⁶² The concept of war in contemporary history and international law, Geneva, 1956, pp. 84 ff.Google Scholar

⁶³ A contribution to the new edition of the Dictionnaire de droit international, edited by Jean Salmon and Eric David.